Organ wind-chest



? Oct. 14, 1969 D. w. COGSWELL 3,472,115

ORGAN WIND-CHEST Filed June 21, 1966 a Sheets-Sheet 1 i l-I I NV ENTOR v} IJUWEILULU smell IE1:fi- El 5:]. awfi z 1969 D. w. COGSWELL 3,47

ORGAN WIND-CHEST Filed June 21, 1966 3 Sheets-Sheet 3 INVENTOR lluvld lLLE gamefi BY 66 a. ri mz M01017) United States Patent 3,472,115 ORGAN WIND-CHEST David W. Cogswell, 8 Maple St., North Wilbraham, Mass. 01067 Filed June 21, 1966, Ser. No. 559,243 Int. Cl. G10b 3/10 U.S. Cl. 84-340 8 Claims ABSTRACT OF THE DISCLOSURE An action for organs wherein a single action member is employed in association with each pipe of said organ to cause each of the pipes to speak. Each of said action members is a fluid amplifier which is designed so as to receive pneumatic signals from the various keys and stops of said organ and combine said signals to cause the pipes to speak.

BACKGROUND This invention relates to organ wind-chests; particularly, it relates to a wind-chest having a unique action for controlling the supply of air to the various pipes of the organ.

Down through the years, indeed centuries, there have been a number of organ actions devised. Basically, they were of the following types: (1) hydraulic, (2) mechanical, (3) tubular-pneumatic, (4) electro-pneumatic, and (5) direct electric. In essence, each of the above noted actions involves a particular system of controlling air flow to organ pipes in order to sound them in response to actuation of the organ control system.

While the electro-pneumatic action is most common today, the mechanical action known as the Tracker Action is probably the best known. Typically, a Tracker Action wind-chest is a rectangular shaped box supplied with air under pressure from a bellows. In a Tracker Action wind-chest there are two sets of valves which control the admission of compressed air or wind to the organ pipes. One set of these valves includes a plurality of valves called pallets each of which controls the wind to all pipes of a particular note. The other set of valves are called sliders each of which is usually located between the pallet and the foot of the pipes. Each slider controls the access of the wind to a series of pipes, commonly referred to as a stop. A pallet is operated by depressing a key on the keyboard, while a slider is operated by the movement of an organ stop knob.

While a Tracker Action is desirable for a number of reasons, such as touch control and tone qualities, it does have a number of significant drawbacks. For example, as the keys and the stop knobs are mechanically connected to the pallets and sliders, the keyboard for practical reasons has to be close to the wind-chest. Also, its basic design gives rise to undesirably high key forces, and being a mechanical action, it tends to be quite noisy. While all of the preceding are significant, the most significant drawback lies in the high expense of construction which is brought about by complexity of the masses of trackers and cranks connecting the keys and stops to the windchest-different in design for each installation.

In an effort to overcome the disadvantages of the Tracker Action, other actions including the tubularpneumatic and electro-pneumatic were developed. In the tubular-pneumatic action, the mechanical linkages between the keys and their respective pallets and the stop knobs and their respective sliders were replaced with conduits for transmitting low pressure pneumatic impulses. In the electro-pneumatic action, electric impulses carried by wires to an electro-magnet are employed to operate the pallets. While both of these methods eliminated the noise and distance problems of the mechanical action, they in turn gave rise to some new problems. In the case of the tubular-pneumatic action, it was found that highflow impulses traveled relatively slowly accounting for poor response, especially as the distance between the keyboard and the wind-chest is increased. As for the electropneumatic action, while it appeared to solve the distance problem and was quick to respond, it became inoperative due to improper contact seating caused by dust and dirt collecting on the contact surfaces of both the electrical devices and the pneumatic relay valves involved.

Another disadvantage associated with the existing electro-pneumatic action appears in the difficulty of borrowing a stop normally played from one keyboard with its stop control for another keyboard having a borrowed stop which permits the first named stop to be played independently on the second keyboard with or without the borrowed stop also playing on the first keyboard. Present systems designed for borrowing are not only complicated, both electrically and mechanically, but are also very expensive and lower the reliability of the action. Because of the effect borrowing has on the tonal quality of the organ pipes and the above considerations of difiiculty and reliability, borrowing is now considered to be cheap and of poor design. However, judicious and limited borrowing can improve an organs versatility and lower its cost.

One further disadvantage, considered major in nature, which is common to all organ actions subsequent to the Tracker Action, involves the use of valve diaphragms made of leather. As will be readily apparent, leather deteriorates with age and is adversely affected by impurities and contaminantes commonly found in the air in todays industrial society, and therefore must be periodically replaced which involves a ditficult, time consuming and expensive operation. While it would appear that some suitable synthetic material could be used to replace the leather, this is not the case. This stems from the fact that conventional wind-chests operate on very low pressure differentials, sometimes on the order of less than 2 inches of water. Therefore, only an extremely compliant longlife material would give the desired results. Down through the history of the organ, the only suitable material has been leather. It is today still leather.

Finally, as none of the actions described above lend themselves to mass production techniques, they are in fact costly to manufacture.

In light of the above, an object of this invention is to provide a new action which is highly reliable in its operation and simple and economical to manufacture, main tain and repair.

A further object of this invention is to provide an action for an organ wind-chest that will permit maximum beauty of tonal quality and speech attack of the pipes.

Another object of this invention is to provide a low cost action which can be readily mass produced.

A further object of this invention is to provide an action for an organ wind-chest which is almost devoid of moving parts, and leather diaphragms.

A still further object of the invention is to provide an organ action whereby borrowing may be employed without the sacrifice of space, structure, cost or performance of the stop being borrowed.

The above and other related objects and advantages will be more readily apparent from the following description and with reference to the accompanying drawings, in which FIG. 1 is a diagrammatical drawing of a wind-chest with appurtenant controls;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a partial sectional view taken along the line 44 of FIG. 1;

FIG. 5 is an end view with sections broken away, taken along the line 55 of FIG. 4; and

FIG. 6 is a further embodiment of the invention.

Referring to FIG. 1 in detail, a wind-chest is generally designated at 10. As is further shown, the wind-chest 10 is connected by a conduit 12 to a stop board 14 having stop knobs 14a, 14b, 14c and 14d, and by a second conduit 16 to key console 18.

The air or wind supply which is conducted to the wind-chest 10 by conduit 24 is provided by a high compression blower 20, which feeds a wind reservoir 22. As shown, the blower 20 also supplies air under pressure by means of conduit 26 to the stop board 14 and key console 18. An exhaust collector 28 completes the system by providing an air return from the wind-chest to the intake side of the blower 20. Additional make-up air is provided to the blower 20 by intake 29.

The wind-chest 10 comprises a plurality of top boards 30a, 30b, 30c and 30d, each of which has a plurality of spaced holes or openings 32 for receiving the pipes of an organ. The wind-chest also includes end wall 34, a front and back wall 36 and 38, respectively, a bottom board 40, and a plurality of parallel partitions 42. In order to simplify further discussion, top board 30a will be hereinafter referred to as stop A, corresponding to stop knob 14a, top board 30b will be referred to as stop B, corresponding to stop knob 14b, etc. Referring particularly to the four stops shown, it will be noted that each has thirteen pipe holes. Traveling from left to right on the stops each pipe hole 32 corresponds to a key such as, C, Cit, D, Di, etc. of the key console 18 have. As depicted, the wind-chest 10 and key console 18 have, for reasons of simplicity, been limited to a single octave (i.e., C to C). However, as is usually the case, an actual wind-chest would encompass more than a single octave.

In FIGS. 4 and 5, it will be seen that directly under each pipe hole 32 which support the organ pipes 44, are action members or blocks 46 to be further described below. The partitions 42 which extend from the front wall 36 to the back wall 38 of the wind-chest 10 define wind or note channels or chambers 48 for the various notes. The air supply is furnished to the note channels 48 from the wind reservoir 22 via conduit 24 (FIG. 1) to the wind-chest 10 through passages 50. The partitioning enables a constant pipe-blowing pressure to be maintained for each note and provides an isolated acoustical path. thereby improving the acoustical intimacy between pipes of different stops sounding on the same note. This particular advantage was only previously available in wind-chests of the pallet-and-slider type.

Turning now to the structure of the action members 46 per se, it will be noted in FIGS. 4 and 5 that they are disposed within the note channels 48 directly beneath each pipe hole 32. The particular type of action member 46 depicted may be referred to as a fluid amplifier of the proportional, dual control type in that its theory of operation lies in the controlled flow of fluids. By the use of the theory of fluidics it has been observed that a valve system, such as that shown, can be used to obtain many of the advantages of the Tracker Action and subsequent actions referred to above but without the many disadvantages of these conventional organ actions.

As mentioned above, an action member 46 is positioned beneath each pipe hole 32. It is the function of the action members 46 to control the flow of wind to the pipes 44. This function is directly accomplished by the movement of a valve head or member 52 in and out of contact with the pipe holes 32. As shown, the valve member is affixed to a flexible diaphragm 54 which completely closes and seals a valve control chamber 56 formed in the upper portion of the action member 46. As shown, biasing member 58, such as a spring, is employed to urge the valve member 52 to its normally closed position. The movement of the diaphragm 54 and afiixed valve member is occasioned by controlling the pressure differential between the control chamber 56 and the note channel 48. The pressure diiferential control is accomplished by operation of the fluid amplifier section of the action members 46.

The fluid amplifier section of the action member 46 comprises a plurality of channels or passages which communicate directly or indirectly with the control chamber 56. As shown, pneumatic signals coming from the stop board 14 and the key console 18 enter the action member through stop-flow channel 70 and key-flow channel 72 respectively and are conducted to the central portion of the action members by said channels. The stop-flow channel 70 enters a junction of three other channels, passes into dump channel 71 and finally to return channel 74, which permits the pneumatic signals to be conducted out of the action members to exhaust conduits 64. The key-flow channel 72 intersects the stop-flow channel 70 at the above mentioned junction opposite a fourth channel known as an output channel 76. The output channel, having its entrance in part defined by a splitter 78 slightly downstream of the intersection of the stop-flow and key-flow channels 70 and 72 respectively, also passes into the return channel 74. A control chamber exhaust channel 80 connects the control chamber '56 with the output channel 76. As shown in FIG. 4, a venturi 86 is disposed in the output channel 76 at or adjacent the mouth of channel 80. Under certain conditions to be later described, the venturi or ejector 86 enables air in the control chamber to be exhausted.

A further and more sophisticated embodiment of the action members 46 of the present invention is shown in FIG. 6. In order to simplify the discussion of the particular design, elements common to the action members of FIG. 4 will be assigned the same reference numerals.

As shown, the action member 46 is positioned below each pipe hole 32 and employs a valve member 52 affixed to a flexible diaphragm 54 spanning a cavity in the block 46 to provide a valve control chamber 56 containing a valve biasing member 58 to hold the valve normally closed. A stop-flow channel 70 which receives pneumatic signals from the stop board 14 enters a junction of three other channels and continues through the junction to a dump channel 71 and return channel 74, which in turn connects to an exhaust conduit 64. A keyfiow channel 72 intersects the stop-flow channel 70 at the above mentioned junction. A fourth channel known as an output channel 76 extends from the junction and has its entrance in part defined by a splitter 78 slightly downstream of the intersection of the stop-flow and keyflow channels 70 and 72 respectively. The output channel 76 also connects to the return channel 74. A control chamber exhaust channel 80 connects the control chamber 56 with the return channel 74. As shown in FIG. 6, a venturi 86 is disposed at the inner end of channel 80 and is met by the downstream end of output channel 76. A bias channel 84 connects the control chamber 56 with the stop-flow channel 70, while channel 83 provides a constant negative bias between the stop-flow channel 70 and the dump channel 71. Pneumatic flow in channels and 77 provide positive biasing assistance to channel from key-flow and stop-flow channels 72 and 70 respectively. Generally speaking, pneumatic flow in channels 75, 77, 83 and 84 serve to adjust the signals in the main channels in order to achieve desired pneumatic control of the valve action.

Cavities or pockets 79 are provided in the walls of channels 71 and 76 to reduce skin attraction to air flow passing through the dump or output channels.

Finally, an optional channelling system is provided so that the borrowing concept as previously described may be employed if desired. As shown in FIG. 6, channel 88 passes to return channel 74 at a point adjacent the venturi 86, and it is supplied by a borrow channel 90 which is connected to a keyboard diiferent than that relating to key channel 66 and stop channel 62 of the action member 46. This system is included only in action members associated with a stop to be borrowed.

Basically, the action members of FIG. 4 and FIG. 6 operate and are controlled in the same manner, therefore, all further discussion will be limited to the action member of FIG. 4 in order to simplify matters.

CONTROL In order to initiate changes in pressure in the control chamber 56, is is necessary to activate the passage of air through the action member 46. As mentioned earlier, the fluid amplifiers of this invention are of the dualcontrol, proportional type. Because it is so designed, there are two modes of control that may be exerted in the action members 46. The first mode of control is employed by actuating any of the stop knobs 14a, 14b, 140, or 14d on the stop board '14. When this is done, high pressure air leading to the stop board via conduit 26 is permitted to pass by a valve (not shown) operated by the actuated stop knob, to a smaller conduit 60a, 60b, 60c, or 60d disposed within conduit 12, see FIG. 2. This pneumatic signal is conducted to the wind-chest by the conduits 60a, 60b, 60c and 60d and conducted through the top boards thereby to all action members 46. A conduit 62 located in end wall 34 and partitions 42 conducts the pneumatic signal to each of the action members. This air which enters stop-flow channels 70 flows through the action member 46 and due to the aerodynamic and fluid jet dimensions in the cavity of the action members 46, it is conducted via dump channel 71 and return channel 74 to the exhaust channels 64 to be carried away by the exhaust collector 28 without causing any further reaction. While channel 70 is large enough to prevent very little pressure or flow to be built up on output channel 76, any slight pressure in channel 76 merely tends to increase the pressure in control chamber 56, thereby holding the valve member 52 even more tightly closed. 7

The second mode of control that may be exerted in the action members 46 is achieved by delivering another signal of high pressure air to the action members 46 via conduits 66 also located in the end wall 34 and partitions 42. This is accomplished by actuating a key (e.g., Cit) on the key console 18 which opens a valve (not shown) allowing high pressure air from conduit 26 to pass to a smaller conduit 66, disposed within conduit 16 (FIG. 3), corresponding to the actuated keys. The air from conduits 66 enters all the action members 46 of a particular note through key-flow channels 72. However, as it is admitted in such small quantities no essential flow or pressure builds up in either channel 71 or channel 76 and therefore the air escapes by way of either passage via return channel 74 to the exhaust channels 64 described above, without causing any further reaction.

In light of the above, it should be clear that if an organist actuates the stops 14a, 14b, 140, and/or 14d, or if he actuates the keys on the key console 18 the pipes of the organ will not sound, as neither of these operations alone will cause the valve member 52 to unseat. Rather, the only flow of air will be in and out of the action blocks 46.

In the event that one or more stops are actuated, and one or more keys are depressed on the key console 18, it should also be clear that both modes of control, described above, may be exerted in the action members 46 at the same time; when this is done, the following sequence takes place. High pressure air enters the action members 46 through channels 70 and 72. Upon meeting at a point upstream of the splitter edge 78, the air in channel 72 offsets and provides additional positive bias to deflect the larger jet of air from channel 70 so that the majority of the combined flow proceeds through output channel 76 rather than dump channel 71 to exhaust conduit 64 via return channel 74. As the combined air flow passes the venturi 86 located adjacent the mouth of channel 80, a venturi effect is created causing a high negative pressure (vacuum) in the control chamber 56, whereby the positive pressure, supplied by holes 50 to the note channels 48, overcomes the force of the biasing member 58, causing the diaphragm 54 to collapse, and opening the valve member 52. This action permits air in the note channel 48 to pass out the pipe holes 32 to the pipes 44, causing them to speak. When air from either channel 70 or channel 72 is cut off, the venturi action is terminated causing normal pressure to build up again in the control chamber 56, which in conjunction with the biasing member 48 firmly closes the valve member 52. It should be noted, that the venturi 86 need not be present, rather the design configuration at the mouth of channel need only be an ejector in that it aids in exhausting the air from the control chamber 56.

OPERATION In order to more clearly state the dynamics of the entire operation, it will be assumed an organist wants to sound the noted Cit in the first stop position, Stop A. First of all, in the system depicted in FIG. 1, the blower 20 is activated in order to deliver air to the wind reservoir 22, which in turn establishes the proper pressures in the note channels 48 and conduits 26 leading to valve assemblies (not shown) for the stop knobs 14a, 14b, 14c, and 14d on the stop board 14 and the various notes on the key console 18. As the valve members 52 are all seated against their top board 30a, 30b, 30c, and 30d, and the stop knobs have not been actuated, there is not escape of air from the wind-chest 10 at any point and consequently no pipes will sound.

At this point, the organist activates stop 14, on the stop board 14, which in turn permits a pneumatic signal to pass through conduit 60a disposed in conduit 12 to channels 70 of the various action members 46 in Stop A. Now, when note Cit on the key console 18 is depressed another pneumatic signal is carried to channel 72 in the action members of the note Cii via one of the conduits 66, disposed in conduit 16, whereby in the action member for the note Cit, Stop A, the air passing through channel 70 into dump channel 71 is deflected by the air of channel 72 at a point upstream of splitter 78 into the output passage 76. As the resultant air flow passes the venturi 86 it causes a venturi effect in channel 80. This effect produces a reduction in the pressure, by exhausting the air in the control chamber 56, thereby collapsing the diaphragm 54 with the attached valve member 52. At this point, air in the note channel 48 passes out the pipe hole 32 causing pipe 44 for the note Cit to sound.

The actions described above are ideally quick and positive. However, in order to achieve maximum beauty of tonal quality and speech attack of the pipes, it is desirable to control the valve opening vs. time and valve closing vs. time characteristics. By the use of fluid amplifier technology, it is possible to schedule opening and closing motions of the valve members 52 by scheduling the delay and return of pressure in the control chamber 56. This may be accomplished in a number of ways, most of which involve the use of pneumatic biasing and feedback similar to those employed in electronic circuitry. As shown in FIG. 6, channels 75, 77, 83, and 84 are such biasing channels. As the characteristics mentioned above are subject to control when fluid amplifiers are employed, it is possible to analyze the pressure-time relationships in existing ideal arrangements in the pallet-and-slider type windchests and to emulate them in the present wind-chest design by the employment of elaborate but inexpensive biasing designs.

As mentioned earlier, by the use of fluid amplifiers, it is now feasible to mass produce the action members at a relatively low cost. For example, as the action members almost devoid of moving parts outside of the diaphragm 54 over the control chamber 56, the blocks may be made of any suitable material, such as molded plastic. As for the diaphragm itself, since the pressure difierentials applied are higher than in previous organ wind-chest designs, it may be made from a variety of materials in sheet form, such as synthetic plastics. In any event the use of leather is no longer required. Finally, the conduits that carry the various pneumatic signals may also be constructed from synthetic materials.

While the description of this invention has concerned itself mainly with the system depicted in the drawings, it is to be understood that changes may be made by those having knowledge in the art. For example, it is within the scope of this invention to employ two separate windsupply systems rather than the single system shown, one such system being of high pressure for use in operating the signals to the action members per se and the other system used only to sound the pipes of the organ. As another example, design changes in the operation and control of the fluid amplifiers are also contemplated. One such change could involve the direct channeling of the air, which makes up the signals, to the action members. If this were done, the admission of the air to the action members would be remotely controlled by electrically operated valves actuated by contact switches in association with the various stops and keys. This variation would reduce the length of the air supply system for the action members.

Having thus disclosed the invention, what is claimed is:

1. For an organ having selectable stops and key console, a wind-chest having a plurality of pipe holes, valve means for each of said pipe holes for controlling the flow of air from said wind-chest through said pipe holes, and means for maintaining a positive pressure in said windchest, the improvement which comprises a fluid amplifier in association with said valve means for actuating said valve means in response to the dual actuation of both said selectable stops and a key of said key console, said fluid amplifier operating under pressures independent of said pressure in said wind-chest.

2. Action for an organ having selectable stops, keys, a wind-chest having a plurality of pipe holes and means for maintaining a positive pressure in said wind-chest, said action comprising a movable valve member for each of said pipe holes, valve control means for moving said valve member and single pneumatic means to actuate said valve control means by receiving separate pneumatic flows controlled by said selectable stops and by said keys and combining said pneumatic flows for said actuation.

3. The organ action of claim 2 in which said single pneumatic means includes an action member, a first channel for carrying pneumatic signals controlled by said selectable stops through said action member, a second channel for introducing pneumatic impulses controlled by said keys into said first channel, a third channel for receiving the combined signal of the signal of said first channel and the impulses of said second channel, and means disposed in said third channel for actuating said valve control means in response to said combined signal in said third channel thereby moving said valve member.

4. The organ action of claim 3 in which said valve control means includes a valve control chamber disposed in said action member, a flexible diaphragm enclosing said valve control chamber, said valve member being aflixed to said flexible diaphragm and movable therewith, a channel connecting said valve control chamber and said third channel and in which said actuating means is an ejector disposed in said third channel adjacent the intersection of said third channel and said channel connecting said valve control chamber with said third channel so that signals in said third channel upon passing said ejector exhausts the air in said valve control chamber and collapses the flexible diaphragm and moves the affixed valve member.

5. For an organ having selectable stops and key console, 9. wind-chest having a plurality of pipe holes, a movable valve member for each of said pipe holes, and means for maintaining a positive pressure in said windchest, the improvement which comprises pressure responsive means for moving said valve member, pressure diflerential control means for actuating said pressure responsive means, said pressure differential control means including two pneumatic signals, one of said signals being generated by actuating a selectable stop, and the other of said signals being generated by actuating a key of said console, said signal generated by said key being directed to deflect said other pneumatic signal thereby creating said pressure differential and causing said pressure responsive means to move said valve member.

6. The improvement for an organ as given in claim 5 wherein said pressure diflerential means includes a fluid amplifier.

7. Action for organs having a key console, stop valve mechanism and wind-chest with organ pipe holes, said action comprising a pneumatically operated valve for each of said pipe holes, a pneumatic circuit interconnecting said key console, stop valve mechanism and windchest, said circuit including a first channel for receiving pneumatic stop signals from the stop mechanism, a second channel communicating with said first channel for injecting a pneumatic key signal from a key of said console into said first channel and deflecting said stop signal, and means for receiving said deflected stop signal and operating said valve.

8. Action for an organ having selectable stops, keys, and a wind-chest having a plurality of pipe holes, said action comprising means for sounding each of said pipes and a fluid amplifier disposed in operable connection with each of said sounding means for actuating said sounding means in response to the dual actuation of both said selectable stops and said keys.

References Cited UNITED STATES PATENTS 802,333 10/1905 Slawik 84-340 3,176,920 4/1965 Severson 13781.5

RICHARD B. WILKINSON, Primary Examiner L. R. FRANKLIN, Assistant Examiner US. Cl. X.R. 84-359 

